This invention relates to an apparatus in which fiber tufts are separated from an airstream and which feeds a lap, for example, to a carding machine. Such an apparatus comprises a feed chute supplied with fiber tufts from a pneumatic conveyor duct coupled to an inlet end of the feed chute. The feed chute has a generally vertical orientation and has at its lower end a delivering device which discharges the tufts from the feed chute as a continuous lap. The feed chute further has, at least on one side, an apertured separating wall through which a downwardly flowing airstream is removed from the feed chute. The separating wall has vertically oriented spaced slots for achieving, over the entire width of the feed chute, a uniform downward progression of a fiber tuft column.
A known apparatus of the above-outlined type is disclosed in German Auslegeschrift (application published after examination) No. 1,286,436. The apparatus disclosed therein has a comb-like separating wall whose narrow vertical slots have a width (for example, 0.5 to 1.5 mm) which is smaller than the expected smallest size of the tufts to be deposited within the chute. By virtue of the width dimension of the slots the fiber tufts are prevented from leaving the feed chute upstream of the delivering device to thus ensure that fiber material will not be lost; rather, the tufts are retained by the teeth of the comb, that is, by the webs between the slots. It is a disadvantage of this arrangement that the narrow slots significantly limit the flow rate of air leaving the feed chute through the separating wall. The degree of compression (densification) and thus a uniformity of the fiber tuft column in the feed chute is, however, dependent upon the product of the speed and the volume of the air flowing in the feed chute, so that a small flow rate of exiting air has an adverse effect on the degree of compression of the fiber tufts.